Archive for gas industry

Statoil Takes Helm at Eagle Ford Asset

Posted in Gas Industry, Oil Drilling, R&J Technical Services with tags , , , , , , on July 1, 2013 by amandarandjtech
by  Statoil ASA

Press Release


Monday, July 01, 2013

Statoil announced Monday that the company as of July 1 has assumed operatorship for all activities in the eastern part of its Eagle Ford asset in Texas. The Statoil-operated activities fall mainly within Live Oak, Karnes, DeWitt and Bee counties.

“This is an important milestone for Statoil’s development as an operator in the U.S.,” said senior vice president for U.S. Onshore, Torstein Hole.

“We now have operational activities in all our onshore assets, Bakken, Marcellus and Eagle Ford. Our organization in Houston is eager to further develop our Eagle Ford holding as operator and we look forward to engaging with communities and landowners in the eastern part of our joint venture acreage,” he underlined.

Statoil entered into the Eagle Ford shale in 2010, through a 50/50 joint venture with Talisman Energy USA Inc. Talisman initially acted as operator for the jointly owned acreage, under an agreement where Statoil was to attain operatorship for half the acreage at a later stage.

Last year, the companies agreed that Statoil, through a phased transition, would take responsibility for operations in the eastern half of the asset.

This acreage falls mainly within Live Oak, Karnes, DeWitt and Bee counties. Talisman will continue with operational responsibility for the western acreage, which is principally in McMullen, La Salle and Dimmit counties. The joint ownership for the total acreage is not impacted by the splitting of operational responsibilities.

Statoil has already taken over operations on three drilling rigs in the Eagle Ford. From July 1 the company has also assumed responsibility for producing wells, processing facilities, pipelines and infrastructure, and a field office in Runge, Karnes County.

Statoil Takes Helm at Eagle Ford Asset

“Both companies have been committed to executing the transition in a safe and responsible manner, whilst ensuring maximum value creation in the joint venture. We are also committed to continue the relationship and further develop strong ties with our host communities,” said Torstein Hole.

Statoil holds approximately 73,000 net acres in the Eagle Ford. Production stands at 20,200 barrels of oil equivalents per day (boepd) (Statoil share) from around 300 producing wells.

Statoil has been active in U.S. shale plays since 2008. Besides its activity in the Eagle Ford, Statoil holds significant positions in the Marcellus and the Bakken plays. Production from these positions is a strong contributor to Statoil’s North American growth strategy, where the ambition is to produce more than 500,000 boepd in 2020. Statoil’s global ambition is to produce 2.5 million boepd in 2020.

In North America, Statoil is established with U.S. offices in Houston and Austin, Texas; Stamford, Connecticut; Anchorage, Alaska; Williston, North Dakota and Washington DC and Canadian offices in Calgary, Alberta and St. Johns, Newfoundland and Labrador.

The company also owns and operates the South Riding Point crude oil terminal in the Bahamas and has a representative office in Mexico City, Mexico.


Bakken Oil Show

Posted in Uncategorized with tags , , , on September 21, 2012 by amandarandjtech

It’s that time of year again fort he Bakken Oil Show!  R & J will be there, with a chance for you to meet some of the founders and decision makers of the company.  The show is in Williston North Dakota, at the Raymond Family Community Center, located at 1002 11th St. West, Williston, ND 58801.  The dates of the show are October 10th and 11th.   If you’ll be in the area, stop by and see us and make sure to enter to win our prize!  Last year we raffled off a rifle.  To learn more about the show, please visit their website


Can the U.S. Be Energy Independent?

Posted in Gas Industry, Oil Drilling with tags , , , on May 11, 2012 by amandarandjtech
by  Karen Boman

Rigzone Staff


Monday, May 07, 2012


As the United States finds itself with abundant natural gas supply and growing domestic oil production, the phrase ‘energy independence’ has become the new buzzword of politicians and oil and gas industry officials.

According to a recent Raymond James report, the United States could achieve energy independence by the end of the decade, Dow Jones reported in early April.

But can the United States truly become energy independent?

In the short to medium term outlook for oil, the United States effectively has no chance of becoming energy independent, said Dr. Michael Noel, senior vice president of Edgeworth Economics.

“Right now, we import so much oil because it’s cheaper to do so,” Noel said. “To forego a cheaper source of oil and replace it with a necessarily more expensive source generally does not make economic sense.”

The argument for energy independence implies that the Unites States should always pay a premium on energy to avoid Middle East oil instead of just a premium when price shocks coming from the Middle East cause price spikes in the United States.

“It’s an expensive insurance policy and that’s why we still use Middle East oil,” Dr. Noel commented, adding that, as long as the United States uses oil to a certain degree, the United States will always be subject to global oil shocks.

Currently, 20 percent of oil imported by the United States comes from the Middle East and 40 percent from OPEC member countries. Canadian oil comprises 20 percent of U.S. imports and is expected to keep growing. Ten percent of U.S. oil imports come from Mexico; the amount of oil imported continues to fall.

Even if the United States imported all of its oil from friendly countries such as Canada, a supply cut in the Middle East would mean customers in this region would need to source oil from somewhere else, bidding up the price of oil and drawing supply from Canada and other friendly countries. As a result, U.S. customers would be impacted with higher prices.

“The domestic price of oil will reflect the world price of oil, so thinking that more domestic drilling will bring domestic oil prices down is a bit naïve,” said John Z. Wetmore, producer for “Perils for Pedestrians” Television, a television series that examines the issues affecting people who walk.

Additionally, the faster the United States pumps its domestic reserves out of the ground, the sooner it will exhaust them and be even more dependent on foreign supplies, Wetmore commented in a statement.

Assertions by some politicians that U.S. energy independence means the U.S. will not have to send its troops over to the Middle East are not accurate, given the United States support of Israel.

“There is still going to be some involvement, given that a number of Muslim countries don’t like its existence,” Noel said.

“Energy independence doesn’t mean we’ll abandon our friends and allies around the world,” said Mike Amman, a Florida-based business finance and technology consultant. “Isolationism isn’t the answer, we’re joined at the hip (or at the wellhead) to the rest of the world, like it or not.”

The outlook is not good for cheap gasoline, given worldwide demand for oil. Wetmore noted that China is now a larger automobile market than the United States and India.

Other countries are trying hard to catch up with United States’ driving habits, Wetmore commented.

“Four dollars will look cheap when the world economy recovers,” said Wetmore. “It would all be more tolerable if we designed our cities and towns with more transportation choices, so we didn’t have to burn gasoline every time we made any trip for any purpose.”

Chris Nelder, an energy expert who has written numerous articles in the topic of Peak Oil, said that existing data doesn’t support the idea of the United States being energy independent.

Nelder questions whether production forecasts for unconventional oil plays such as the Bakken are feasible, and notes that Mexico’s production has been in long term decline.

While tight oil wells have huge initial production rates, they decline sharply in six months times. Tight oil production will also not work with lower oil prices.

“To be energy independent, we would have to produce about 9 million barrels of oil per day (bopd) from wells that give you 100 bopd,” Nelder noted, adding that oil prices need to stay above at least $85 per barrel to sustain production.

However, higher oil prices have also bolstered gasoline prices, and as U.S. consumers struggle with $4/gallon prices, they start to drive less, which kills demand. Oil production needs to remain on a narrow ledge to keep production flowing, and the incredible price swings to above $100 and below $85 impact supply.

“In that narrow band, do we really think it’s possible that for another decade we can drill thousands and thousands of wells?” said Nelder.

To keep output flat, the U.S. would have to draw down its oil resources more quickly, Nelder commented.. By 2030 and 2040, over two-thirds of the world’s oil fields will be in terminal decline. At that time, the United States will face difficulties in importing oil from anywhere.

“From that point, we’re going to need our domestic resources,” said Nelder. “We could actually be shooting ourselves by trying to achieve energy independence.”

Promise of Natural Gas?

The United States already is energy independent in natural gas, said ConocoPhillips Chairman and CEO James Mulva at a recent conference.

Energy industry leaders such as T. Boone Pickens and Robert Hefner are calling for greater use of natural gas in the United States in transportation.

Nelder thinks that T. Boone Picken’s plan to convert fleet vehicles to run on compressed natural gas makes a lot of sense, but worries that the deluge of natural gas that as resulted from the shale gas rush means that no companies can make money on natural gas.

The land rush mentality that ensued since late 2010 resulted in companies buying up a number of properties and drilling. A lot of gas is being flared, and plans have been proposed to convert liquefied natural gas import terminals constructed in the United States into export terminals.

Nelder said he thinks that the United States shouldn’t get crazy about exporting LNG until the United States really knows what it has in terms of supply, noting that the 100 years of natural gas supply in the United States hasn’t been proven and is highly speculative.

The United States already uses gas that is the equivalent of 11 million barrels of oil per day and faces the serious risk of finding itself faced with very expensive gas if gas use increases and LNG is exported.

A number of shale gas producers such as Chesapeake Energy have taken on a lot debt to acquire shale gas properties, thinking they can flip the leases. But these companies face the real possibility of going bankrupt when buyers start to question whether the can profitably produce gas, Nelder noted.


Original article found here

Mr. President, Now That We Need It, Give Us Our Oil Back

Posted in Gas Industry, Oil Drilling with tags , , , , , on April 13, 2012 by amandarandjtech

Raymond J. Learsy




Friday, April 13, 2012

  • Iran is cheering
  • Speculators are profiting
  • Oil producers celebrating
  • Our nascent economy tottering
  • Household budgets being ripped apart
  • Home owners in Maine freezing

You are sitting on some 700 million barrels of oil in our Strategic Petroleum Reserve (SPR) bought and paid by both the 99% and even the 1%.

Here we are living an economic and political emergency while the tool we have to deal with this issue remains untapped.

A reasonable release from the SPR would immediately drop the price of oil significantly and in turn keep gasoline prices from rising further in the months ahead and very possibly keep the economic recovery on track. In June 2011, when the Department of Energy announced it would be releasing 30 million barrels of oil, the price of oil dropped almost immediately by $4.00/barrel (“White House to release 30M barrels of oil” Politico 06.23.11) sending the speculators running for the hills.

Back then when the release was announced Speaker of the House John Boehner bridled:

Everyone wants to help the American people and lower prices at the pump — especially now, in tough economic times. And it is good that the Obama Administration is conceding that increased supply will lower those costs. But by tapping the Strategic Petroleum Reserve, the President is using a national security instrument to address his domestic political problems. The SPR was created to mitigate sudden supply disruptions. This action threatens our ability to respond to a genuine national security crisis and means we must ultimately find the resources to replenish the reserve — at significant cost to taxpayers.

This time around Mr. Boehner and everyone else should understand high, ever higher, oil prices are Iran’s most effective weapon. It will help the mullahs realize the cash flow they need to maintain their authoritarian rule while playing nuclear roulette. Embargoing swaths of their oil exports will have little or no impact if their saber rattling, together with the help of the oil speculators, pushes oil prices to ever higher highs.

Mr. President, pull the plug on the SPR now, and let the oil flow.

Raymond J. Learsy is the author of Oil and Finance: The Epic Corruption Continues and Over a Barrel: Breaking Oil’s Grip on Our Future. He has worked as a commodities trader, private investor and is currently a member of the Woodrow Wilson International Center for Scholars. Learn more at

Original article found here

Limits of Technology in Drilling

Posted in Gas Industry, Oil Drilling with tags , , , , on March 23, 2012 by amandarandjtech

Drill technology has advanced steadily since the 19th century. However, there are several basic limiting factors which will determine the depth to which a bore hole can be sunk.

All holes must maintain outer diameter; the diameter of the hole must remain wider than the diameter of the rods or the rods cannot turn in the hole and progress cannot continue. Friction caused by the drilling operation will tend to reduce the outside diameter of the drill bit. This applies to all drilling methods, except that in diamond core drilling the use of thinner rods and casing may permit the hole to continue. Casing is simply a hollow sheath which protects the hole against collapse during drilling, and is made of metal or PVC. Often diamond holes will start off at a large diameter and when outside diameter is lost, thinner rods put down inside casing to continue, until finally the hole becomes too narrow. Alternatively, the hole can be reamed; this is the usual practice in oil well drilling where the hole size is maintained down to the next casing point.

For percussion techniques, the main limitation is air pressure. Air must be delivered to the piston at sufficient pressure to activate the reciprocating action, and in turn drive the head into the rock with sufficient strength to fracture and pulverise it. With depth, volume is added to the in-rod string, requiring larger compressors to achieve operational pressures. Secondly, groundwater is ubiquitous, and increases in pressure with depth in the ground. The air inside the rod string must be pressurised enough to overcome this water pressure at the bit face. Then, the air must be able to carry the rock fragments to surface. This is why depths in excess of 500 m for reverse circulation drilling are rarely achieved, because the cost is prohibitive and approaches the threshold at which diamond core drilling is more economic.

Diamond drilling can routinely achieve depths in excess of 1200 m. In cases where money is no issue, extreme depths have been achieved, because there is no requirement to overcome water pressure. However, circulation must be maintained to return the drill cuttings to surface, and more importantly to maintain cooling and lubrication of the cutting surface.

Without sufficient lubrication and cooling, the matrix of the drill bit will soften. While diamond is the hardest substance known, at 10 on the Mohs hardness scale, it must remain firmly in the matrix to achieve cutting. Weight on bit, the force exerted on the cutting face of the bit by the drill rods in the hole above the bit, must also be monitored.

File:@hand rig.jpg

Drilling Types

Posted in Gas Industry, Oil Drilling, Uncategorized with tags , , , , , on March 16, 2012 by amandarandjtech

There are a variety of drill mechanisms which can be used to sink a borehole into the ground. Each has its advantages and disadvantages, in terms of the depth to which it can drill, the type of sample returned, the costs involved and penetration rates achieved. There are two basic types of drills: drills which produce rock chips, and drills which produce core samples.

Auger drilling

Auger drilling is done with a helical screw which is driven into the ground with rotation; the earth is lifted up the borehole by the blade of the screw. Hollow stem auger drilling is used for softer ground such as swamps where the hole will not stay open by itself for environmental drilling, geotechnical drilling, soil engineering and geochemistry reconnaissance work in exploration for mineral deposits. Solid flight augers/bucket augers are used in harder ground construction drilling. In some cases, mine shafts are dug with auger drills. Small augers can be mounted on the back of a utility truck, with large augers used for sinking piles for bridge foundations.

Auger drilling is restricted to generally soft unconsolidated material or weak weathered rock. It is cheap and fast.

Cable tool water well drilling rig in Kimball, West Virginia. These slow rigs have mostly been replaced by rotary drilling rigs in the U.S.

Percussion rotary air blast drilling (RAB)

RAB drilling is used most frequently in the mineral exploration industry. (This tool is also known as a Down-the-hole drill.) The drill uses a pneumatic reciprocating piston-driven “hammer” to energetically drive a heavy drill bit into the rock. The drill bit is hollow, solid steel and has ~20 mm thick tungsten rods protruding from the steel matrix as “buttons”. The tungsten buttons are the cutting face of the bit.

The cuttings are blown up the outside of the rods and collected at surface. Air or a combination of air and foam lift the cuttings.

RAB drilling is used primarily for mineral exploration, water bore drilling and blast-hole drilling in mines, as well as for other applications such as engineering, etc. RAB produces lower quality samples because the cuttings are blown up the outside of the rods and can be contaminated from contact with other rocks. RAB drilling at extreme depth, if it encounters water, may rapidly clog the outside of the hole with debris, precluding removal of drill cuttings from the hole. This can be counteracted, however, with the use of “stabilisers” also known as “reamers”, which are large cylindrical pieces of steel attached to the drill string, and made to perfectly fit the size of the hole being drilled. These have sets of rollers on the side, usually with tungsten buttons, that constantly break down cuttings being pushed upwards.

The use of high-powered air compressors, which push 900-1150 cfm of air at 300-350 psi down the hole also ensures drilling of a deeper hole up to ~1250 m due to higher air pressure which pushes all rock cuttings and any water to the surface. This, of course, is all dependent on the density and weight of the rock being drilled, and on how worn the drill bit is.

Air core drilling

Air core drilling and related methods use hardened steel or tungsten blades to bore a hole into unconsolidated ground. The drill bit has three blades arranged around the bit head, which cut the unconsolidated ground. The rods are hollow and contain an inner tube which sits inside the hollow outer rod barrel. The drill cuttings are removed by injection of compressed air into the hole via the annular area between the innertube and the drill rod. The cuttings are then blown back to surface up the inner tube where they pass through the sample separating system and are collected if needed. Drilling continues with the addition of rods to the top of the drill string. Air core drilling can occasionally produce small chunks of cored rock.

This method of drilling is used to drill the weathered regolith, as the drill rig and steel or tungsten blades cannot penetrate fresh rock. Where possible, air core drilling is preferred over RAB drilling as it provides a more representative sample. Air core drilling can achieve depths approaching 300 meters in good conditions. As the cuttings are removed inside the rods and are less prone to contamination compared to conventional drilling where the cuttings pass to the surface via outside return between the outside of the drill rod and the walls of the hole. This method is more costly and slower than RAB.

Cable tool drilling

SpeedStar cable tool drilling rig, Ballston Spa, New York

Cable tool rigs are a traditional way of drilling water wells. The majority of large diameter water supply wells, especially deep wells completed in bedrock aquifers, were completed using this drilling method. Although this drilling method has largely been supplanted in recent years by other, faster drilling techniques, it is still the most practicable drilling method for large diameter, deep bedrock wells, and in widespread use for small rural water supply wells. The impact of the drill bit fractures the rock and in many shale rock situations increases the water flow into a well over rotary.

Also known as ballistic well drilling and sometimes called “spudders”, these rigs raise and drop a drill string with a heavy carbide tipped drilling bit that chisels through the rock by finely pulverizing the subsurface materials. The drill string is composed of the upper drill rods, a set of “jars” (inter-locking “sliders” that help transmit additional energy to the drill bit and assist in removing the bit if it is stuck) and the drill bit. During the drilling process, the drill string is periodically removed from the borehole and a bailer is lowered to collect the drill cuttings (rock fragments, soil, etc.). The bailer is a bucket-like tool with a trapdoor in the base. If the borehole is dry, water is added so that the drill cuttings will flow into the bailer. When lifted, the trapdoor closes and the cuttings are then raised and removed. Since the drill string must be raised and lowered to advance the boring, the casing (larger diameter outer piping) is typically used to hold back upper soil materials and stabilize the borehole.

Cable tool rigs are simpler and cheaper than similarly sized rotary rigs, although loud and very slow to operate. The world record cable tool well was drilled in New York to a depth of almost 12,000 feet (3,700 m). The common Bucyrus Erie 22 can drill down to about 1,100 feet (340 m). Since cable tool drilling does not use air to eject the drilling chips like a rotary, instead using a cable strung bailer, technically there is no limitation on depth.

Cable tool rigs now are nearly obsolete in the United States. They are mostly used in Africa or Third-World countries. Being slow, cable tool rig drilling means increased wages for drillers. In the United States drilling wages would average around US$200 per day per man, while in Africa it is only US$6 per day per man, so a slow drilling machine can still be used in undeveloped countries with depressed wages. A cable tool rig can drill 25 feet (7.6 m) to 60 feet (18 m) of hard rock a day. A newer rotary drillcat top head rig equipped with down-the-hole (DTH) hammer can drill 500 feet (150 m) or more per day, depending on size and formation hardness.

Reverse circulation (RC) drilling

Reverse Circulation (RC) rig, outside Newman, Western Australia

Track mounted Reverse Circulation rig (side view).

RC drilling is similar to air core drilling, in that the drill cuttings are returned to surface inside the rods. The drilling mechanism is a pneumatic reciprocating piston known as a “hammer” driving a tungsten-steel drill bit. RC drilling utilises much larger rigs and machinery and depths of up to 500 metres are routinely achieved. RC drilling ideally produces dry rock chips, as large air compressors dry the rock out ahead of the advancing drill bit. RC drilling is slower and costlier but achieves better penetration than RAB or air core drilling; it is cheaper than diamond coring and is thus preferred for most mineral exploration work.

Reverse circulation is achieved by blowing air down the rods, the differential pressure creating air lift of the water and cuttings up the “inner tube”, which is inside each rod. It reaches the “bell” at the top of the hole, then moves through a sample hose which is attached to the top of the “cyclone”. The drill cuttings travel around the inside of the cyclone until they fall through an opening at the bottom and are collected in a sample bag.

The most commonly used RC drill bits are 5-8 inches (13–20 cm) in diameter and have round metal ‘buttons’ that protrude from the bit, which are required to drill through shale and abrasive rock. As the buttons wear down, drilling becomes slower and the rod string can potentially become bogged in the hole. This is a problem as trying to recover the rods may take hours and in some cases weeks. The rods and drill bits themselves are very expensive, often resulting in great cost to drilling companies when equipment is lost down the bore hole. Most companies will regularly re-grind the buttons on their drill bits in order to prevent this, and to speed up progress. Usually, when something is lost (breaks off) in the hole, it is not the drill string, but rather from the bit, hammer, or stabiliser to the bottom of the drill string (bit). This is usually caused by a blunt bit getting stuck in fresh rock, over-stressed metal, or a fresh drill bit getting stuck in a part of the hole that is too small, owing to having used a bit that has worn to smaller than the desired hole diameter.

Although RC drilling is air-powered, water is also used, to reduce dust, keep the drill bit cool, and assist in pushing cutting back upwards, but also when “collaring” a new hole. A mud called “Liqui-Pol” is mixed with water and pumped into the rod string, down the hole. This helps to bring up the sample to the surface by making the sand stick together. Occasionally, “Super-Foam” (a.k.a. “Quik-Foam”) is also used, to bring all the very fine cuttings to the surface, and to clean the hole. When the drill reaches hard rock, a “collar” is put down the hole around the rods, which is normally PVC piping. Occasionally the collar may be made from metal casing. Collaring a hole is needed to stop the walls from caving in and bogging the rod string at the top of the hole. Collars may be up to 60 metres deep, depending on the ground, although if drilling through hard rock a collar may not be necessary.

Reverse circulation rig setups usually consist of a support vehicle, an auxiliary vehicle, as well as the rig itself. The support vehicle, normally a truck, holds diesel and water tanks for resupplying the rig. It also holds other supplies needed for maintenance on the rig. The auxiliary is a vehicle, carrying an auxiliary engine and a booster engine. These engines are connected to the rig by high pressure air hoses. Although RC rigs have their own booster and compressor to generate air pressure, extra power is needed which usually isn’t supplied by the rig due to lack of space for these large engines. Instead, the engines are mounted on the auxiliary vehicle. Compressors on an RC rig have an output of around 1000 cfm at 500 psi (500 L·s−1 at 3.4 MPa). Alternatively, stand-alone air compressors which have an output of 900-1150cfm at 300-350 psi each are used in sets of 2, 3, or 4, which are all routed to the rig through a multi-valve manifold.

Diamond core drilling

Multi-combination drilling rig (capable of both diamond and reverse circulation drilling). Rig is currently set up for diamond drilling.

Diamond core drilling (exploration diamond drilling) utilizes an annular diamond-impregnated drill bit attached to the end of hollow drill rods to cut a cylindrical core of solid rock. The diamonds used are fine to microfine industrial grade diamonds. They are set within a matrix of varying hardness, from brass to high-grade steel. Matrix hardness, diamond size and dosing can be varied according to the rock which must be cut. Holes within the bit allow water to be delivered to the cutting face. This provides three essential functions — lubrication, cooling, and removal of drill cuttings from the hole.

Diamond drilling is much slower than reverse circulation (RC) drilling due to the hardness of the ground being drilled. Drilling of 1200 to 1800 metres is common and at these depths, ground is mainly hard rock. Diamond rigs need to drill slowly to lengthen the life of drill bits and rods, which are very expensive.

Core samples are retrieved via the use of a core tube, a hollow tube placed inside the rod string and pumped with water until it locks into the core barrel. As the core is drilled, the core barrel slides over the core as it is cut. An “overshot” attached to the end of the winch cable is lowered inside the rod string and locks on to the backend(aka head assembly), located on the top end of the core barrel. The winch is retracted, pulling the core tube to the surface. The core does not drop out of the inside of the core tube when lifted because either a split ring core lifter or basket retainer allow the core to move into, but not back out of the tube.


Diamond core drill bits

Once the core tube is removed from the hole, the core sample is then removed from the core tube and catalogued. The Driller’s assistant unscrews the backend off the core tube using tube wrenches, then each part of the tube is taken and the core is shaken out into core trays. The core is washed, measured and broken into smaller pieces using a hammer or sawn through to make it fit into the sample trays. Once catalogued, the core trays are retrieved by geologists who then analyse the core and determine if the drill site is a good location to expand future mining operations.

Diamond rigs can also be part of a multi-combination rig. Multi-combination rigs are a dual setup rig capable of operating in either a reverse circulation (RC) and diamond drilling role (though not at the same time). This is a common scenario where exploration drilling is being performed in a very isolated location. The rig is first set up to drill as an RC rig and once the desired metres are drilled, the rig is set up for diamond drilling. This way the deeper metres of the hole can be drilled without moving the rig and waiting for a diamond rig to set up on the pad.

Direct push rigs

Direct push technology includes several types of drilling rigs and drilling equipment which advances a drill string by pushing or hammering without rotating the drill string. While this does not meet the proper definition of drilling, it does achieve the same result — a borehole. Direct push rigs include both cone penetration testing (CPT) rigs and direct push sampling rigs such as a PowerProbe or Geoprobe. Direct push rigs typically are limited to drilling in unconsolidated soil materials and very soft rock.

CPT rigs advance specialized testing equipment (such as electronic cones), and soil samplers using large hydraulic rams. Most CPT rigs are heavily ballasted (20 metric tons is typical) as a counter force against the pushing force of the hydraulic rams which are often rated up to 20 kN. Alternatively, small, light CPT rigs and offshore CPT rigs will use anchors such as screwed-in ground anchors to create the reactive force. In ideal conditions, CPT rigs can achieve production rates of up to 250–300 meters per day.

Direct push drilling rigs use hydraulic cylinders and a hydraulic hammer in advancing a hollow core sampler to gather soil and groundwater samples. The speed and depth of penetration is largely dependent on the soil type, the size of the sampler, and the weight and power the rig. Direct push techniques are generally limited to shallow soil sample recovery in unconsolidated soil materials. The advantage of direct push technology is that in the right soil type it can produce a large number of high quality samples quickly and cheaply, generally from 50 to 75 meters per day. Rather than hammering, direct push can also be combined with sonic (vibratory) methods to increase drill efficiency.

Hydraulic rotary drilling

Oil well drilling utilises tri-cone roller, carbide embedded, fixed-cutter diamond, or diamond-impregnated drill bits to wear away at the cutting face. This is preferred because there is no need to return intact samples to surface for assay as the objective is to reach a formation containing oil or natural gas. Sizable machinery is used, enabling depths of several kilometres to be penetrated. Rotating hollow drill pipes carry down bentonite and barite infused drilling muds to lubricate, cool, and clean the drilling bit, control downhole pressures, stabilize the wall of the borehole and remove drill cuttings. The mud travels back to the surface around the outside of the drill pipe, called the annulus. Examining rock chips extracted from the mud is known as mud logging. Another form of well logging is electronic and is frequently employed to evaluate the existence of possible oil and gas deposits in the borehole. This can take place while the well is being drilled, using Measurement While Drilling tools, or after drilling, by lowering measurement tools into the newly drilled hole.

The rotary system of drilling was in general use in Texas in the early 1900s. It is a modification of one invented by Fauvelle in 1845, and used in the early years of the oil industry in some of the oil-producing countries in Europe. Originally pressurized water was used instead of mud, and was almost useless in hard rock before the diamond cutting bit.[2] The main breakthrough for rotary drilling came in 1901, when Anthony Francis Lucas combined the use of a steam-driven rig and of mud instead of water in the Spindletop discovery well.

The drilling and production of oil and gas can pose a safety risk and a hazard to the environment from the ignition of the entrained gas causing dangerous fires and also from the risk of oil leakage polluting water, land and groundwater. For these reasons, redundant safety systems and highly trained personnel are required by law in all countries with significant production.

Sonic (vibratory) drilling

A sonic drill head works by sending high frequency resonant vibrations down the drill string to the drill bit, while the operator controls these frequencies to suit the specific conditions of the soil/rock geology. Vibrations may also be generated within the drill head. The frequency is generally between 50 and 120 hertz (cycles per second) and can be varied by the operator.

Resonance magnifies the amplitude of the drill bit, which fluidizes the soil particles at the bit face, allowing for fast and easy penetration through most geological formations. An internal spring system isolates these vibrational forces from the rest of the drill rig.

Drilling rig classification

Posted in Gas Industry, Oil Drilling, R&J Technical Services with tags , , , , , , , on March 9, 2012 by amandarandjtech

There are many types and designs of drilling rigs, with many drilling rigs capable of switching or combining different drilling technologies as needed. Drilling rigs can be described using any of the following attributes:

By power used

  • Mechanical — the rig uses torque converters, clutches, and transmissions powered by its own engines, often diesel
  • Electric — the major items of machinery are driven by electric motors, usually with power generated on-site using internal combustion engines
  • Hydraulic — the rig primarily uses hydraulic power
  • Pneumatic — the rig is primarily powered by pressurized air
  • Steam — the rig uses steam-powered engines and pumps (obsolete after middle of 20th Century)

By pipe used

  • Cable — a cable is used to raise and drop the drill bit
  • Conventional — uses metal or plastic drill pipe of varying types
  • Coil tubing — uses a giant coil of tube and a downhole drilling motor

By height

(All rigs drill with only a single pipe. Rigs are differentiated by how many connected pipe they are able to “stand” in the derrick when needing to temporarily remove the drill pipe from the hole. Typically this is done when changing a drill bit or when “logging” the well.)

  • Single — can pull only single drill pipes. The presence or absence of vertical pipe racking “fingers” varies from rig to rig.
  • Double — can hold a stand of pipe in the derrick consisting of two connected drill pipes, called a “double stand”.
  • Triple — can hold a stand of pipe in the derrick consisting of three connected drill pipes, called a “triple stand”.

By method of rotation or drilling method

  • No-rotation includes direct push rigs and most service rigs
  • Rotary table — rotation is achieved by turning a square or hexagonal pipe (the “Kelly”) at drill floor level.
  • Top drive — rotation and circulation is done at the top of the drill string, on a motor that moves in a track along the derrick.
  • Sonic — uses primarily vibratory energy to advance the drill string
  • Hammer — uses rotation and percussive force (see Down-the-hole drill)

By position of derrick

  • Conventional — derrick is vertical
  • Slant — derrick is slanted at a 45 degree angle to facilitate horizontal drilling